The making of internal welds at the joint between abutted pipes is a long standing problem. A number of apparatuses have been designed for this purpose, none of which is particularly satisfactory. It is often difficult to control the path of the weld bead relative the joint to prevent the weld bead from straying from the joint. Manned apparatuses, apparatuses wherein a man is placed within the pipe to control the welding, are unsatisfactory since the environment within the pipe is uncomfortable and somewhat hazardous, and since the weld emissions such as gases and hot metal particles, and the like, make placement of a man within the pipe not to be desired. If the pipes are not very large, there is not sufficient room for a man within the pipes. It is, therefore, desirable to provide an automatic internal welding apparatus which will accurately track the joint between pipe ends and form a weld reliably bridging between the pipe ends, with sufficient weld penetration that the weld is strong, and is uniform so that internal finishing of the weld is not a major problem. This invention seeks to provide an internal welding apparatus, in combination with pipe clamp apparatus, so that the welding may be done at the interior of a weld joint with control thereof at the exteriors of the pipes.